New cassava varieties offer hope to farmers

Nigeria is the world's largest producer of cassava, while Thailand is the largest exporter of cassava starch.

Cassava is a woody shrub of the spurge family native to South America. Although a perennial plant, cassava is extensively cultivated as an annual crop in tropical and subtropical regions for its edible starchy tuberous root, a major source of carbohydrates.   Cassava is predominantly consumed in boiled form, but substantial quantities are used to extract cassava starch, called tapioca, which is used for food, animal feed, and industrial purposes. 

Cassava is classified as either sweet or bitter. Like other roots and tubers, both bitter and sweet varieties of cassava contain antinutritional factors and toxins, with the bitter varieties containing much larger amounts.  It must be properly prepared before consumption, as improper preparation of cassava can leave enough residual cyanide to cause acute cyanide intoxication, goiters, and even ataxia, partial paralysis, or death. The more toxic varieties of cassava are a fall-back resource (a "food security crop") in times of famine or food insecurity in some places.  Farmers often prefer the bitter varieties because they deter pests, animals, and thieves.  

Majority of farmers and a large number of people in Tanzania believe cassava is a very hardy crop that requires little attention when cultivated. A large number of people also think that when you throw cassava cuttings onto any soil in Tanzania you will harvest some roots even if no attention is given to the plants.

Cassava like any other food crop requires attention if optimum (maximum) yields are to be obtained from a unit area. Cassava is affected by a number of diseases that prevent farmers from getting optimum yields of roots from their farms. Some of the diseases are so devastating (destructive) that they can give no yield of storage roots if not controlled.

Cassava diseases are caused by very tiny living things that are so small in size that they can not be seen with the naked eyes. Living things that are very tiny and can not be seen with the naked eyes are said to be microscopic. These microscopic living things causing diseases are called pathogens. Pathogens that cause diseases in cassava may be viruses, bacteria or fungi.

Recently a team of scientists developed a revolutionary new mobile app that uses artificial intelligence to accurately diagnose crop diseases in the field.

The team works under the research programme on climate change, agriculture and food security (CGIAR), Research Programme on roots, tubers and bananas (RTB).

Cassava brown streak disease and cassava mosaic disease are a threat to the food and income security of over 30 million farmers in East and Central Africa. Likewise, banana is threatened by fungal and bacterial diseases including the devastating banana bunchy top virus, while late blight still plagues potato farmers.

Farmers are often unable to properly identify these diseases, while researchers, plant health authorities and extension organisations lack the data to support them.

 The project team has developed linkages with the Vodafone agriculture SMS platform called DigiFarm, which will allow them to link digital diagnostics to large-scale rural text messaging services.

The project we are told is also being carried out by a global network of scientists from IITA, Penn State, the International Institute of Tropical Agriculture (CIAT), the International Potato Centre (CIP) and bioversity international, as part of the CGIAR research programme on roots, tubers and bananas (RTB).